Numerous industries require the transportation and storage of bulk liquid materials. While a variety of large containers are presently used, the most common continues to be the conventional fifty-five gallon drum. Notwithstanding its popularity, the fifty-five gallon drum is known to have disadvantages, including the following: an inefficient use of storage and transportation space, difficulty in handling, the disposal of empty drums, and the necessity of inverting the drum for full discharge.
In recent years, the cubic shaped transportation container has gained increasing popularity. One variety consists of a cubic metal container having an inner, polyethylene tank. While demonstrating an efficient use of storage space, the cubic metal container has also shown limitations. During return, a vast amount of transportation space is "wasted" by the overall bulk of the empty metal container. From a cost standpoint, other limitations also exist. If recycling is desired, separation of the inner polyethylene tank from the outer metal containe is difficult. Additional cost reductions could be achieved through the use of an alternative material for the metal of the container.
Another recent development in bulk liquid transportation is the disposable shipping container. One such container is disclosed in U.S. Pat. No. 4,793,519, assigned to the assignee of the present application. The disposable shipping container of the referenced patent consists of a rectangularly shaped outer container formed of a corrugated paper material. Although less expensive than the previously mentioned metal containers, the corrugated paper container remains strong enough to permit shipping and stacking of the containers. A thin walled, unitary blow molded plastic inner tank lines the interior of th corrugated paper container. So constructed, the outer containe structurally supports and maintains the rectangular shape of the inner plastic tank. Unlike the metal container, upon being emptied the outer container and the inner tank are readily separated for disposing and recycling purposes.
A variation of the above referenced patent is embodied in U.S. patent application Ser. No. 274,425, filed Nov. 21, 1988, also assigned to the assignee of the present invention. In the referenced application, the outer container is constructed of a single layer of solid fiber paperboard. Instead of four distinct side walls, the container of the mentioned application consists of a single continuous upright side wall, rounded at the upright corners and secured to top and bottom walls by metal crimp rings.
While the referenced patent and application are both disposable and recyclable, in a long term continuous supply arrangement, the disposability and/or recyclability of the shipping container may not always be cost beneficial. It is therefore an object of the present invention to provide a reusable container for use in shipping bulk liquid materials one-way.
It is another object of the invention to provide a reusable, bulk liquid shipping container that is durable, yet inexpensive to construct.
It is a further object of the present invention to provide a reusable, bulk liquid shipping container which is capable of efficiently occupying a minimum amount of transportation space during subsequent return to the liquid supplier.
The shipping container of the present invention consists of a rectangularly shaped wire mesh outer container having a bottom wall, upright side walls and a substantially flat top wall. A unitary blow molded plastic inner tank is positioned upright and inside of the wire mesh outer container. While the side walls of the inner tank are substantially thin and thus prevented from being self-supportive, the wire mesh walls of the outer tank are constructed of a sufficient gage to structurally support the inner tank when it is filled with liquid. The inner tank is also equipped with an inlet fitting and a discharge fitting, respectively extending into fill and discharge openings in the wire mesh walls of the outer container.
To facilitate an increased ease in the handling of the container, the outer container has a number of dependent legs, mounted on its bottom wall, which are capable of receiving forklift tines. Additionally, the inner tank has two reinforced support regions positioned on its upper surface. The combination of the inner tank support regions and the gage of the wire mesh outer walls enables two full containers to be stacked upon one another.
The bulk liquid shipping container of the present invention demonstrates numerous advantages over shipping containers previously and presently used in the industry. Namely, the invention is reusable as a one-way shipping container. Upon complete discharge of the contents of the inner tank, a wall of the wire mesh outer container can be opened so as to readily permit the removal of the collapsed inner tank. The polyethylene inner tank may then be either discarded or recycled, whichever is most advantageous from a cost standpoint. Once the inner tank has been removed, the outer tank is capable of folding upon itself, to a substantially reduced height, for maximizing transportation space during return to the original supplier for subsequent reuse.
Additional benefits and advantages of the present invention will become apparent to those skilled in the art to which this invention relates from the subsequent description of the preferred embodiment and the appended claims, taken in conjunction with the accompanying drawings.